Photographer's description:
Sunset behind a rather tall thunderstorm with mammatus clouds at the top.
This is from the top of the hill in Huber Heights (202 & Taylorsville Road)
looking Northwest towards Vandalia.

Mammatus
clouds accompany strong thunderstorms. They are a unique phenomenon since they occur
in sinking air rather than rising air. Strong updrafts in the
thunderstorm transfer ice and snow crystals into the thunderstorm's anvil.
These particles eventually fall out and evaporate, which
causes the air around them to cool. This causes
instability
and convective overturning, which gives the bubbly appearance seen here.